Aquilaria vs Gyrinops: understanding agarwood species

Agarwood is not produced by a single tree species. It comes from a group of related trees in two genera, Aquilaria and Gyrinops, which share the same resin-forming biology covered in how agarwood resin forms. Almost every regional name used in the trade, Vietnamese, Cambodian, Indonesian, Assamese and the rest, ultimately refers to a particular species from one of these genera growing in a particular place.

This guide is the foundation for the regional profiles in this hub. It sets out what distinguishes Aquilaria from Gyrinops, where each is found, and where the science is less tidy than trade marketing suggests.

The two genera behind agarwood

Aquilaria and Gyrinops are responsible for essentially all the agarwood reaching the global market. Botanical references disagree on the exact count: Kew's Plants of the World Online currently accepts 15 Aquilaria species, while other studies list about 21, and around nine Gyrinops species are usually recognised. Counts in actively studied tropical genera shift as research is published.

Aquilaria is by far the more commercially important of the two. Species such as Aquilaria malaccensis, Aquilaria crassna, Aquilaria sinensis and Aquilaria filaria account for most agarwood in international trade. Gyrinops is smaller in species and historical trade volume, but far from a footnote: its species are a major source of agarwood from eastern Indonesia and an increasingly significant part of the Papua New Guinea trade, both covered in their own guides in this hub.

Where they sit in the plant kingdom

Both genera belong to the family Thymelaeaceae, in the order Malvales. Aquilaria was formally described by the French botanist Jean-Baptiste Lamarck in 1788, and Gyrinops by the German botanist Joseph Gaertner in 1791. They have been treated as separate genera for more than two centuries, even though, as later sections explain, the genetic line between them has turned out to be less clean than that long history suggests.

How botanists tell them apart

The traditional character used to separate the two genera is the number of stamens in the flower: Aquilaria flowers have ten, Gyrinops flowers five. Some researchers have pointed out that this single character is not a strong basis for separating genera, which is one reason some have proposed merging them. Either way, these are features of the living tree, used in botanical keys and herbarium work.

It is worth being direct about this: there is no reliable way to look at a chip of agarwood, or smell it, and tell whether it came from an Aquilaria or a Gyrinops tree. Identification happens at the point of harvest, based on the living tree, long before the wood is processed into chips, powder or oil. Once agarwood is in trade, species claims rest on documentation and the seller's knowledge of their sourcing, not on anything a buyer can check by inspection.

Where each genus grows

Aquilaria has much the wider range. Its species are native across northeastern India and Bangladesh, southern China, mainland and island Southeast Asia, the Philippines, Borneo and parts of New Guinea, although no single species covers all of that. Particular species map onto particular countries. Aquilaria crassna is the main species of Vietnam, Laos, Cambodia and Thailand. Aquilaria malaccensis is most associated with Peninsular Malaysia, Assam in northeastern India and large parts of Indonesia. Aquilaria sinensis grows in southern China, and Aquilaria filaria in eastern Indonesia and parts of Papua New Guinea.

Gyrinops is more concentrated, centred on eastern Indonesia. Gyrinops versteegii is one of its most commercially important species and a source of agarwood from islands in Nusa Tenggara such as Lombok, Sumbawa and Flores. Outside Indonesia, Gyrinops walla is native to Sri Lanka and southern India, and Gyrinops ledermannii is a significant source of agarwood in Papua New Guinea, covered in Papua New Guinean agarwood.

Why the distinction matters when you are buying

Regional names in the agarwood trade are, in practice, shorthand for a particular species growing in a particular place. "Cambodian oud" usually implies Aquilaria crassna. Agarwood from Papua New Guinea is now often Gyrinops ledermannii rather than an Aquilaria species. Knowing which genus and species sits behind a regional name gives a buyer a more concrete reference point than the name alone, and it is the framework the rest of this hub is built on. A side by side view is in the regional agarwood comparison.

Scent and quality comparisons between Aquilaria and Gyrinops, or between species of the same genus, are widely discussed among traders and collectors, but much of that discussion is qualitative rather than settled by controlled comparison. The same caution that applies to wild and plantation scent claims, covered in wild vs plantation agarwood, applies here: treat claims that one genus or species is categorically superior as trade opinion, however often they are repeated.

A blurrier line than it looks: what DNA studies show

Although Aquilaria and Gyrinops have been treated as separate genera since the eighteenth century, molecular research has complicated the picture. A 2018 study in Frontiers in Plant Science found that DNA data do not cleanly separate the two genera, consistent with earlier work suggesting their relationship is paraphyletic, and supported reconsidering whether they should be treated as one genus. In plainer terms, the flower feature botanists use to divide them does not necessarily match how closely related the species are at the DNA level.

This is an active area of research rather than a settled reclassification, and it has not changed how the genera are named in trade or in this guide. It is worth knowing mainly because it explains why disagreements over a species' genus turn up in the scientific literature.

Both genera, same legal protection

Whatever their exact evolutionary relationship, Aquilaria and Gyrinops are treated the same under international trade law. Aquilaria malaccensis was the first agarwood species listed in CITES Appendix II, in force from 1995, and every other Aquilaria species and the whole Gyrinops genus were added at the 2004 CITES conference, in force from 2005. The framework is covered in agarwood and CITES explained.